1,720,988 research outputs found
Simulations of the dynamo effect with the lattice Boltzmann method
No full textSimulations of the dynamo effect require the simultaneous integration of the Navier-Stokes equation and of the induction equation of electrodynamics. We present a hybrid method in which the Navier-Stokes equation is solved with a lattice Boltzmann method and the induction equation is treated with a spectral method. (C) 2005 Elsevier Ltd. All rights reserved
Magnetic field oscillation in simulations of the Karlsruhe Dynamo
No full textThe dynamo effect is numerically simulated for a model of the Karlsruhe dynamo. A flow periodic in two directions and independent of the third coordinate is considered. Each periodicity cell contains four helical vortices. The novelty of the model is that it includes cylindrical walls enclosing each vortex. These walls mimic the mechanical constraints inside the Karlsruhe experiment. Periodic oscillations of the magnetic field appear in the course of which the magnetic field pattern in each vortex rotates. The oscillations already exist in the kinematic regime. It is shown that the oscillations found in our simulations and oscillations observed in the Karlsruhe dynamo experiment must be of different origin. (c) 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
‘Mediating Labour: an introduction’
Get PDFThe essays in this volume aim to explain the evolution and persistence of various practices of indirect labour recruitment. Labour intermediation is understood as a global phenomenon, present for many centuries in most countries of the world, and taking on a wide range of forms: varying from outright trafficking to job placement in the context of national employment policies. By focusing on the actual practices of different types of labour mediators in various regions of the world during the nineteenth and twentieth centuries, and by highlighting both the national as well as the international and translocal contexts of these practices, this volume intends to further a historically informed global perspective on the subject
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Labour History and the Case against Colonialism
No full textThe controversy around Bruce Gilley's article The Case for Colonialism has drawn global attention to a stream of revisionist claims and visions on the history of colonialism that has emerged in academia and in the media in recent years. Authors such as Nigel Biggar in the UK, Niall Ferguson in the USA, and Pieter Emmer in the Netherlands, have all published similarly revisionist claims about colonialism, arguing that postcolonial guilt and political correctness blind the majority of their colleagues to the positive side of the colonial project. Their argument chimes with wider societal trends, transforming the revisionist defenders of empire into heroes of a reinvigorated nationalist right within and beyond academia. The public influence attained by these approaches to colonialism requires historians to expose the deep methodological flaws, misreading of historical facts, and misrepresentations of prior scholarship that characterize the writings of this emerging revisionist trend. It is for this reason that the Editorial Committee of the International Review of Social History (IRSH) has decided to devote its first ever Virtual Special Issue to labour history's case against colonialism. This article, also an introduction to the Virtual Special Issue, sifts through the logical implications of the claims made by Gilley and like-minded scholars, providing both a contextualization and a rebuttal of their arguments. After assessing the long absence of colonial labour relations from the field of interest of labour historians and the pages of the IRSH itself, this article shows the centrality of a critique of colonialism to labour history's global turn in the 1990s. Using a selection of articles on colonial labour history from the IRSH's own archive, the article not only reconstructs labour history's case against colonialism, but also shows why labour history's critical insights into the nature of colonialism should be deepened and extended, not discarded.</p
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